The present invention relates to a front wheel driving device of a vehicle, making use of a planetary gear mechanism as the final stage of the speed reduction.
Such a front wheel driving device has been known as making use of a planetary gear system as the final stage of the speed reduction, in order to reduce the size of the gear case while obtaining a sufficiently large speed reduction ratio. This kind of front wheel device is disclosed, for example, in the specification of the U.S. Pat. No. 3,469,647. This type of front wheel driving device, however, is extremely difficult to assemble. For instance, in the known device disclosed in the above-mentioned specification, it is necessary to connect the front wheel axle to the output shaft of the planetary gear mechanism simultaneously with the assembling of the gears of the planetary gear mechanism, because the axial stopper for the front wheel axis is disposed in the vicinity of the inner side of the front wheel axle, i.e. in the vicinity of the point of meshing between the sun gear and the planetary gear. In consequence, the work has to be done in a restricted space and, in addition, the state of meshing of gears in the planetary gear mechanism can hardly be checked.